Science And Faith
by MG12CSI16
Summary: Catherine Willows and her FBI partner find themselves working with NCIS to catch a killer. But when the case takes a turn the teams find themselves heading to Las Vegas and in need of the crime labs help. Co-written with There's A Time Lord In Lima.
1. The Key

A/N: Hey guys, this is my first crossover and I'm pretty excited about it. It's written with a very good friend of mine, There's A Time Lord In Lima. You should check out her other stories. Enjoy!

Chapter 1: The Key

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><p><strong>Science And Faith<strong>

Tobias Fornell was a man on a mission. His infamous scowl was plastered on his face and his heavy footsteps could be heard echoing throughout the corridor.

The file in his hand was labeled classified, and little did he know it held the key for one agent to return home. He entered the bullpen and scanned the rows of desks, each filled with busy agents and secretaries.

His eyes rested on a young agent with wavy brown hair and dark eyes. Seated next to him a strawberry blonde woman he had never seen before. He made a slow approach and extended his hand.

"Tobias Fornell." he said. The young man gave him a firm handshake followed by his companion.

"Sac Pratt. This is my partner Catherine Willows. Anything we can help you with?" he asked. He kept a careful eye on his new aquatance and Fornell couldn't help but admire the kids confidence.

"As a matter of fact there is. A new case just came in. The name Charlie Blackwell ring a bell?" he asked the younger agents. Pratt nodded his head while Catherine sat with a puzzled look on her face.

"Yeah I remember him. Sick son of a bitch." Pratt said, a look of disgust playing up on his face. He looked at Catherine and started explaining.

"Charlie Blackwell surfaced about 5 years ago. He's a serial killer completely fixated on women. He holds them for 2 days an tortured them. His signature is carving a C into there cheek. None of the women seem to be connected and there seems to be no pattern in choosing his victims." he told her. Fornell nodded and handed them the file.

"A body came in this morning matching the MO. Blackwell dropped off the grid right before we were set to make an arrest." he said. Pratt was flipping through the file and suddenly looked up.

"How come nobody's been talking about this?" he asked.

"The woman was a female petty officer. Her body was taken to NCIS, it falls under there jurisdiction. But since we had access first it's become joint jurisdiction." Fornell explained. Catherine looked up, a hint of excitement on her face.

"So we're working with NCIS?" she asked. Fornell nodded and stalked off, leaving the two agents with nothing but the manila envolope.

"Have fun with it!" he called over his shoulder.

"Well this should be exciting." Catherine said, perched on the end of her desk.

" You keep telling yourself that." Pratt said. His eyes were wide as he handed her the file. She took and scanned the pages.

"What's the big deal?" she asked. She handed the file back to him and leaned back.

"Did you read who exactly we're working with?" he asked. She shook her head, a skeptical loom showing in her eyes.

"It says here we're working with Jethro Gibbs. I've seen him make grown men run screaming." he said recalling his one and only encounter with the senior agent. Catherine rolled her eyes and waved him off.

"Come on, theres no way he's that bad." she said. Pratt shot her a look but kept his mouth shut.

"Come on, Lets get some coffee and go over the rest of this file. You need to be informed before we meet with Gibbs." he said.

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><p>Taking their coffee to an open booth in the local cafe Pratt and catherine spread the mound of papers out in front of them. Pratt explained Blackwells history and told Catherine about his almost arrest.<p>

"Forensics had targeted him as the killer and got us a warrant. Apparently he somehow got word and went into hiding, convincing everyone there was a mole in the agency. He's been on the top of our lists ever since." Catherine layed down the paper in her hand and picked up her coffee.

Taking small sips she thought back to the Dick and Jane killer, he had escaped police custody and went into hiding. She just hoped Pratt didn't become obsessed like Langston had.

"So what do you know about agent Gibbs?" she asked. Pratt layed down the file and clasped his hands together.

"I've only met him once, very briefly. He's not to keen on working with others, so this should be an experience to remember." he said while twiddling his thumbs. He stared at her, making her shift uncomfortably under his gaze.

"What?" she asked. He shook his head and leaned back in his seat.

"Nothing. I'm just thinking about how far you've come in the last 3 months." he told her with a smirk. She rolled her eyes and thought back to the long months of training.

She had many lessons in self defense and had to take a shooting test that would put the crime lab to shame. She had passed them all with flying colors and had impressed all the other trainees as well as Pratt.

She remembered seeing him beam with pride when she received her badge. She was a promising agent, very intelligent and always eager to learn.

Pratt admired her greatly, happy he snatched her up when he did. Snapping back to reality the two gathered the file and drained their cups, tossing them in the garbage on the way out.

"Are we going to NCIS now?" she asked. Pratt nodded and unlocked his sleek black car, climbing inside and bringing the engine to life. Catherine followed an did the same. Pratt Shot her a look and asked,

"You ready for this?" She buckled her seat belt and turned to face him.

"Ready as I'll ever be."


	2. Call Me Catherine

Chapter 2: Call Me Catherine

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><p><strong>Science And Faith<strong>

Gibbs slammed the phone back down on his desk. He had just finished talking with Fornell; there was a serial killer murdering women on the run, and his team was going to have to work with the FBI. That was the last thing he wanted to do.

"Something wrong, boss?" Tony dinozzo asked from across the bullpen.

"We've got a case," replied Gibbs. "Serial killer from an old FBI case that's fallen into our jurisdiction."

"What's the problem, then?" asked Timothy McGee.

"We have to work with the FBI." McGee nodded.

"Oh. I guess you're not happy about that, then."

"Do I look happy, McGee?" demanded Gibbs.

The younger agent shook his head. Annoying Gibbs was the last thing anyone wanted to do. "Of course not, I- I was just-"

"So who's our killer?" interrupted Ziva David. "You said he was from an old case."

"The name's Charlie Blackwell. Five years ago he started killing women in DC. The FBI almost had him, but he went into hiding and hasn't been heard from until now."

"Why would he start killing again after five years?" asked Tony. "And why is it in our jurisdiction? Has he always killed marines?"

"No, but he recently murdered a female petty officer in DC," Gibbs told them. "The body's already down in the morgue."

"Hey, duck," announced Gibbs when he entered the bright, cold room.

"Hello, Jethro," replied Dr. Mallard when the field agent entered the morgue. The old M.E. was standing by an examination table with a white sheet covering what was the body of the dead petty officer.

"What have you got?" asked Gibbs. Ducky pulled back the sheet, revealing the face of a once very pretty woman, but it was badly bruised and had a "C" neatly carved into the left cheek.

"Poor thing," ducky whispered sadly. "her name was Molly Perkins, 34 years old and in fairly good health. her body was found just outside of Quantico yesterday. The report says that it appeared to be a dump."

"Cause of death?" asked Gibbs.

"COD was strangulation, and apparently, our killer used some kind of a belt." Ducky showed Gibbs the bruised skin around the woman's throat.

"And as you can see," continued Ducky, "there's also severe bruising on the face, indicating that the girl was badly beaten before he took her life."

"And the marks on her wrists? Looks like she was tied up."

"Indeed. I found fibers in the ligature marks, so I had Palmer send them up to Abby's lab. They're deep, so I'm guessing that she was bound for at least 2 days."

"Blackwell tortures them for two days before he kills them," Gibbs told Ducky. "And then he carves a "C" into their cheek." he looked at Molly Perkin's mutilated face in disgust; he wanted to find the sick bastard who had done this to her and all his past victims.

"You got a TOD, too?" The doctor nodded and covered the body back up. He went to his desk and picked up his chart, scanning the contents.

" Her liver temperature and level of decomposition puts it around two days ago."

"So she was tortured for two days, killed, and then her body was found after another two," said Gibbs."She was missing for at least four days, so why didn't anyone report it?" The doctor merely shrugged his shoulders and turned his attention back to the body.

"Maybe she has no family, or they may not be local." he said.

"I'll have DiNozzo find out more about her. Thanks, duck." Gibbs left the morgue and headed back to the bullpen.

When Gibbs arrived back upstairs to inform his team about ducky's autopsy, he found not only Ziva, Tony, and McGee there, but also two people talking with DiNozzo. They were probably from the FBI. One of them was a young man with wavy brown hair. Gibbs had met him once before, but didn't remember the name.

There was also an older woman, a little bit younger than Gibbs, with long strawberry blonde hair. The man looked a bit uneasy when he saw the senior field agent walk up to them.

"Boss, this is agent Pratt and agent Willows from the FBI," tony said. "they're going to be working with us on the Blackwell case."

"Please, call me Catherine," the woman said to the NCIS agent.

"Jethro Gibbs." he shook Pratt and Catherine's hands.

Pratt nodded stiffly, trying to avoid looking Gibbs in the eye. But Catherine greeted Gibbs warmly.

"It's nice to meet you," she said. "I'm looking forward to working with you, agent Gibbs." Catherine didn't seem too bad, for an FBI agent. Maybe Gibbs would actually like this one.

"Call me Jethro," he said with a slight smile. Catherine returned it.

"So you're new to the FBI?" asked Gibbs.

"Yes, i came here a few months ago from-"

"Boss!" McGee interrupted suddenly from his desk.

"What, McGee?" Gibbs demanded.

Tim placed the phone back down on his desk and hurried over to his supervisor.

"I just got a call from the FBI office in Nevada. It's Blackwell. He was spotted by a police officer but then he disappeared into a crowd. Officials haven't seen any sign of him since."

"Where in Nevada?"

McGee looked around the small group of agents and replied,

"Las Vegas."


	3. Amateurs

Woah, it's been WAY too long since an update. So sorry! Thanks for the reviews and alerts. Enjoy!

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><p><strong>Science And Faith<strong>

"Grab your gear!" barked Gibbs, heading towards his desk. Ziva, Tony, and McGee all looked back and forth at one another in confusion.

"But, Gibbs," Tony began, "we just got that call, I don't think we-"

"Need to leave right now. Yes we do, DiNozzo," snapped Gibbs. "We have a serial killer on the loose and we know where he is!"

Gibbs slung his bag over his shoulder and looked back at his team. "Well?"

Taking immediate note of the seriousness in their boss's voice, the three field agents hurried to their desks and went for their gear like Gibbs ordered. Catherine and Pratt remained where they stood, unsure exactly what to do.

"By the way," a voice said in Catherine's ear. She turned to see that it was Gibbs. "Where were you going to say you were from?"

"Oh." Catherine didn't know whether she should tell them the truth or not. Of course, Pratt already knew she was from Vegas; that was where they had met. Catherine wouldn't really be lying if she didn't tell them.

"Um, it's, uh... not important right now," she finally answered. "Besides, we've got a killer to catch."

Conrad Ecklie slumped back in his seat, slamming the phone back onto the cradle. Rubbing a hand over his thinning hair he let out a breath, looking up and seeing D.B Russell standing in the doorway.

"Yeah Russell? What can I do for ya?" his tone held a hint of frustration, dark cirlces forming under his eyes.

"I'm here to drop off those case files you asked for." The older man stepped inside, laying down the folders. "You alright? You're looking a little rough." he commented, throwing him a friendly smile.

Conrad sat up, pulling the files toward him. He looked at the phone, then back to Russell, sighing and beckoning the man forward.

"I just got a call from the Sherriff, apparently a serial killer from D.C. managed to skip town and hide in Vegas. FBI and NCIS are lending a hand in the investigation, they should be here soon to debrief you and your team."

Russell puffed out his cheeks, mentally assesing the situation.

"NCIS you said? I'm not to familair with that agency." Conrad chuckled, pushing back his seat to perch on the end of his desk.

"Naval Criminal Investigative Service. Navy cops basically." he finished.

"And the Navy ties into this because?"

"Last victim, killed about two to three days ago was a petty officer. Female by the name of Molly Perkins." He pulled out a photograph and slid it across the table.

"Oh man, he really went to work on her." Russell commented, noting the cut and ligature marks.

"His signature is carving a C into their cheek after they've been tortured for two days before he finally strangles them." He pulled out another file, reading it aloud.

"The ligature marks found on the victims neck appear to be made by an item similar to a belt or scarf. Fibers were taken from the wounds and were sent to trace." He put the paper down and folded his hands. "Those were the autopsy reults from the coronrer at NCIS."

"Any word on what they were?" Condrad shrugged, putting his coffee mug to his lips. Swallowing he stood and paced his small office.

"Now, this case is going to bring alot of attention to the city. I don't want the citizens fearing for their lives because there's a killer on the loose." His voice was stern as he wagged a finger.

"Come on Conrad, you're acting like we're amatures." Russell joked, letting his booming laugh fill the room.

"Don't push it." His pager beeped, pulling it off his hip he waved it in Russells face.

"Looks like their here."


End file.
